team germany's (technische universität darmstadt) surplushome

the school's solar decathlon 2009 house integrates design with technology in one seamless process.

Coming off of its overall victory at the 2007 Solar Decathlon, Team Germany probably felt pressure to top themselves with a hip house and even hipper technology. And who could blame them? Fortunately, this year's house, surPLUShome, could likely garner the team another win.

Like many of the homes in the competition, surPLUShome features an open floor plan design, but the German team made a commitment to the style. The home "is based on a single room concept," the school writes. "The interior design is characterized by a multi-functional body as its central element. This body contains primary functions like the kitchen, stairs, and the bath and defines the possible use of close-by space. Besides it takes over functions of furniture and the building services."

Student Frauke Rottschy says the idea was "to create a room that was wide open, so that we have only the bathroom that you can shut, while every other room is visible from the others."

Unlike other houses in the competition, this one has two levels including a loft. It also has a bed and other furniture and appliances that fold away or serve multiple purposes, the team adds.

Incorporating design and technology was part of the program from the beginning, Rottschy says. "We tried to build a house where every technical system was integrated," she says.

The most obvious way the team did this is through the striking exterior cladding of the home, which is covered with about 250 thin-film copper indium gallium diselenide panels. An 11.1-kilowatt system made up of 40 single-crystal silicon panels is installed on the roof. Slightly less efficient than the silicon, the thin-film shingles will perform better in cloudy weather, the school says.

Rottschy says the "goal of the competition is to gain as much energy as possible so we thought of a [photovoltaic] system that could also work in the façade" as well as augment those on the roof. The plan obviously worked: The school says the two systems are expected to produce 200% of the energy needed by the house.